/Engine/Source/Editor/UnrealEd/Public/Subsystems/AssetEditorSubsystem.h
Close any editor which is not this one
void CloseOtherEditors ( [UObject](API\Runtime\CoreUObject\UObject\UObject) * Asset, [IAssetEditorInstance](API\Editor\UnrealEd\Subsystems\IAssetEditorInstance) * OnlyEditor )